Archive for category: News

Expanding the 2D flatlands: toward MBene Li- and Na-ion batteries 🔋

In our ongoing research to identify sustainable technological alternatives 🌱, we have explored the potential of layered boride materials (MoAlB and Mo2AlB2) for their use in Lithium-ion and Sodium-ion batteries (LIBs and SIBs) 🔬. Great to see our Open Access paper now appeared in print in Small Methods! 🖨️

Some key findings from the paper include:
👉Unlike MXene, no HF is needed for the 3D-to-2D etching reaction🧪
👉Sodium hydroxide treatment applied to MoAlB results in a porous morphology 🍯, leading to higher specific capacities than its original form
👉Mo2AlB2 showcases a more promising specific capacity compared to MoAlB for LIBs, registering a specific capacity of 593 mAh/g after 500 cycles at 200 mA/g ⚡
👉When it comes to SIBs, Mo2AlB2 demonstrated a specific capacity of 150 mA/g at 20 mA/g 📊.
These findings underscore the potential of layered borides as an interesting electrode materials for both LIBs and SIBs, and illuminate 🔦 the significance of surface redox reactions in Li storage mechanisms.

A sincere thank you 🙏 to our amazing partners for their invaluable contributions and collaboration.

Tulane University:
Ahmad Majed
Chukwudi Nwaokorie
Karamullah Eisawi
Audrey Buck
Matthew Montemore
Michael Naguib

INM-Leibniz Institute for New Materials:
Mohammad Torkamanzadeh
Volker Presser

Berkeley Lab:
Chaochao Dun
Jeff Urban

New review paper published in Industrial Chemistry & Materials on utilizing the electrochemical quartz crystal microbalance (EQCM) to better understand the charge/discharge processes in supercapacitors.

Supercapacitors are renowned for their exceptional attributes, including high power density, fast charging capabilities, and remarkable cycling stability. To further enhance their potential, it is crucial to comprehend the intricacies of their charging processes. The EQCM, with its nanogram-level in situ mass change information, has played a pivotal role in unraveling these mechanisms.

Our paper provides a comprehensive review of the progress made in EQCM, covering theoretical fundamentals and its applications in supercapacitors. We also delve into the fundamental effects of ion desolvation and transport, shedding light on their impact on supercapacitor performance.

By thoroughly examining the advantages and limitations of EQCM in supercapacitors, we present a holistic view of this groundbreaking technique. Moreover, we propose future directions for further exploration in this dynamic field.

This work was done in collaboration with our long-time collaborator Guang Feng from the Interface and Transport Phenomena (ITP) Laboratory at Huazhong University of Science and Technology (HUST).

New paper published in Advanced Materials Interfaces on mechanisms in high-performance tin oxide / MXene batteries. As the demand for power and energy storage continues to grow, we researchers are constantly exploring new ways to improve battery performance. One promising approach involves using conversion/alloying materials, such as tin oxide, to design high-performance lithium-ion batteries. While these materials show excellent performance and ease of preparation, they often suffer from mechanical instabilities during cycling that limits their usefulness. This issue can be addressed (and overcome) by combining tin oxide with MXene.
In this study, we prepared a 50/50 (by mass) tin oxide / Ti-MXene (SnO₂/Ti₃C₂T_z) nanocomposite and optimized it as a negative electrode for lithium-ion batteries. The result? A nanocomposite that delivers over 500 mAh/g for 700 cycles at 0.1 A/g and demonstrates excellent rate capability, with 340 mAh/g at 8 A/g.
The success of this nanocomposite lies in the synergistic behavior of its two components, which we confirmed through ex situ chemical, structural, and morphological analyses. Not only does this knowledge allow us to formulate a reaction mechanism with lithium-ions that provides partial reversibility of the conversion reaction, but it also opens up new possibilities for designing high-performance lithium-ion batteries.

Thanks to our great team of collaborators:

Team Ricerca sul Sistema Energetico – RSE SpA & Università degli Studi di Milano-Bicocca:
Antonio Gentile
Chiara Ferrara
Stefano Marchionna
Riccardo Ruffo

Team INM-Leibniz Institute for New Materials:
Stefanie Arnold
Volker Presser

Team Karlsruhe Institute of Technology (KIT)
Yushu Tang
Julia Maibach
Christian Kübel

New paper published in npj Materials Degradation (open access). In cooperation with the group of Frank Mücklich at Saarland University and partners, we have found that coating laser-patterned stainless-steel surfaces with carbon nanotubes (CNT) or carbon onions (CO) can create an effective solid lubrication system. By storing the particles inside the pattern, lubricant retention is improved and depletion in the contact area is prevented. In previous works, we used laser interference patterning to create line patterns with different depths and coated them with CNTs or COs. Friction tests were conducted to study the effect of structural depth on the lubricity of these surfaces, and we found that shallower textures result in lower friction coefficients. Our latest study examines the degradation of the carbon nanoparticles on substrates with different structural depths, and Raman characterization shows severe degradation of both particle types. This degradation is classified within Ferrari’s three-stage amorphization model. Electron microscopy also confirms that CNT lubricity is improved at the cost of increasing particle defectivity, while CO-derived tribofilms experience even more substantial structural degradation.

Our research team has published an article in ChemSusChem on the promising use of stable and efficient SnO₂ electrodes for degrading refractory organic pollutants in wastewater treatment. Our approach involved the preparation of Ti³⁺ self-doped urchin-like rutile TiO₂ nanoclusters (TiO_2-xNCs) on a Ti mesh substrate using hydrothermal and electroreduction methods, which served as an interlayer for the deposition of Sb-SnO₂. Our TiO_2-xNCs/Sb-SnO₂ anode exhibited a high oxygen evolution potential and strong *OH generation ability, resulting in improved degradation performance for rhodamine B, methylene blue, alizarin yellow R, and methyl orange. Our unique rutile interlayer also extended the anode lifetime sixfold due to its good lattice match with SnO₂ and three-dimensional concave-convex structure. Overall, our work highlights the importance of designing interlayer crystal forms and structures for achieving efficient and stable SnO₂ electrodes in addressing dye wastewater problems. This work was done in collaboration with our colleagues from Chongqing University.

New perspective paper published in Communications Materials. The high entropy concept is ideally suited for MXenes but also capable to be a unique tool to tailor and improve electrochemical properties in other materials.

Multiple principal element or high-entropy materials have recently been studied in the two-dimensional (2D) materials phase space. These promising classes of materials combine the unique behavior of solid-solution and entropy-stabilized systems with high aspect ratios and atomically thin characteristics of 2D materials. The current experimental space of these materials includes 2D transition metal oxides, carbides/carbonitrides/nitrides (MXenes), dichalcogenides, and hydrotalcites. However, high-entropy 2D materials have the potential to expand into other types, such as 2D metal-organic frameworks, 2D transition metal carbo-chalcogenides, and 2D transition metal borides (MBenes).

So, what is our perspective article about? We discuss the entropy stabilization from bulk to 2D systems, the effects of disordered multi-valent elements on lattice distortion and local electronic structures and elucidate how these local changes influence the catalytic and electrochemical behavior of these 2D high-entropy materials. We also provide a perspective on 2D high-entropy materials research and its challenges and discuss the importance of this emerging field of nanomaterials in designing tunable compositions with unique electronic structures for energy, catalytic, electronic, and structural applications.

This perspective paper has been the result of our collaboration with my dear friend Babak Anasori (with his team: Kartik Nemani and Brian Wyatt) from Purdue University and our team (including Mohammad Torkamanzadeh).

New paper published in the Journal of the American Ceramic Society on the synthesis of new hybrid electrode materials for Li-ion batteries (LIBs). Through controlled oxidation of layered Ti₂SnC, we were able to obtain TiO₂-SnO₂-C/carbide hybrid materials using two different methods: partial oxidation in an open-air furnace (OAF) and rapid thermal annealing (RTA). The resulting carbide phase included both residual Ti₂SnC and TiC as a reaction product. In testing, we found that the sample oxidized in the OAF at 700°C for 1 hour had the highest initial lithiation capacity of 838 mAh/g at 100 mA/g. However, its delithiation capacity decreased to 427 mAh/g over cycling. In contrast, the RTA sample treated at 800°C for 30 seconds demonstrated the most efficient performance, with a reversible capacity of approximately 270 mAh/g after 150 cycles and a specific capacity of about 150 mAh/g under high cycling rate (2000 mA/g). Our findings suggest that this processing method could have wide-ranging applications in energy storage, particularly for other members of the MAX family. This work was the latest product of collaboration with the team of Michael Naguib (Tulane University, USA).